120mm Double Ball Bearing Fan- The previous Yate Loon fans that came in these S12s were sleeve bearing types. Seasonic informed me that the change was made in order to reduce reject rates on the production line and in the field, and to improve consistency.

Long-lived Aluminum Electrolytic Capacitor- Apparently, higher quality Japanese aluminum electrolytic capacitors are now used for greater reliability and stable performance. More common China-made capacitors must have been used before, as is typical of most PSUs. There have been major incidents of electronics, including motherboards, affected by leaking capacitors sourced from China starting from ~2 years ago.

Both of these items are examined here in light of the potential impact on the acoustic and thermal performance of the S12-430.There is one other change that does not affect thermal performance: 20+4 Pin Main Connector - Rather than provide a 24-pin connector and a clumsy 24-to-20 pin adapter, this connector switches back and forth easily from 20 pin to 24 pin.

The "new and improved" S12-430 looks unchanged externally. Internally, the ADDA fan was the only change noted. I did see a couple of Japanese capacitors but no photo was taken.

New ADDA fan in all the S12 models. The three lower rated models get the
slow speed fan.

We could discuss the various differences between this new fan and the earlier Yate Loon fan, but it would be more expedient to go directly to PSU testing results. Yes, the new sample was strapped into the SPCR PSU test rig and put through a full round of testing.

NOTE: The ambient room temperature during testing varies
a few degrees from review to review. Please take this into account when
comparing PSU test data.

Only the most salient information is presented in the table above for simplicity's sake. The test data from the original sample (on the previous page) is presented in brackets.

EFFICIENCY: It's clear that that the efficiency curves of the two samples are not quite the same. The new sample starts a bit lower, catches up at about half power load, then stays at a bit higher efficiency out to max power. The difference could be attributed to the new Japanese aluminum electrolytic capacitors or to increased airflow from the new fan; it is also small enough that sample variance and tolerances within SPCR's testing procedures could be suspected. In any case, it's a negligible difference, especially in actual use. (The actually wattage differences are mostly <5W AC.)

NOISE: The differences in SPL readings and in perceived noise are audible. At minimum speed, the new Adda fan is very nearly the equal of the earlier Yate Loon, but it remains a bit louder all the way throughout the power range. The measured difference is 2~3 dBA/1m except at the highest loads. Subjectively, the difference seems smaller than this. The Adda fan has a bit more buzz while the Yate Loon seems to have a bit more whoosh.

Between 300W and 430W, the fan in the first version barely gets any louder; the new Adda-fan version climbs a very significant +5 dBA/1m. The increased noise is comprised entirely of wind turbulence noise, which suggests that the maximum airflow of the new fan is higher than that of the older fan, and it has more cooling power in reserve at max power load. In practical terms, this discussion regarding noise at max load is not significant; even a very power hungry single VGA card system will rarely draw 250W, and as the S12-430 and its smaller variants do not offer the 6-pin PCIe connector, they will not be used for dual VGA SLI systems.

As mentioned. the Adda fan seems to have a touch more of a buzzy quality than the Yate Loon, but it is subtle and you must be very close to hear it. Beyond the low 20 dBA range, the wind turbulence noise tends to swamp over differences. Without the early Yate Loon version S12 to compare directly against, I could only say that this is "new and improved" S12-430 is one heck of a quiet PSU. If this is the cost of a little extra reliability and longevity, I doubt anyone will be aware of even paying the price.

POSTCRIPT #2: Efficiency CorrectionOctober 22, 2005

Recently, we discovered that our power supply testing equipment and methodology were providing erroneously high efficiency results. In general, the biggest errors occurred at higher
output load points above 300W. At lower output levels, the efficiency error
was often no more than one or two percentage points. No other tested parameters were significantly affected.

Through a fairly arduous process of discovery, analysis and old fashioned problem solving, we modified our testing equipment and methodology to improve the accuracy of the efficiency results and described it all in the article SPCR's PSU Test Platform V.3. As part of this revision, we re-tested most of the power supplies on our Recommended PSU List. In most cases, the same sample was used in the second test.

The corrected and original efficiency results for all the re-tested PSUs are shown in in the article, Corrected Efficiency Results for Recommended Power Supplies. The relative efficiency of the tested power supplies has not changed.
If the tested PSUs are ranked by efficiency, the rankings remain the same whether we use the original results or the new results.

This
data is also being added to relevant reviews as postscripts like this one.

CORRECTED EFFICIENCY: Seasonic S12-430

Target Output

65W

90W

150W

200W

250W

300W

400W

Actual Output

65.8W

90.9W

151.7W

203.6W

261.7W

299.3W

427.2W*

Efficiency

Corrected

78.3%

80.5%

81.6%

81.8%

80.5%

79.6%

75.5%

Original

77%

78%

79%

82%

82%

80%

80%

In this case, our original efficiency calculations were 1.3~2.5% too low through to about 200W output. Above that, the original results were slightly too high, with the worst error of 4.5 percentage points off at full output power. The new figures suggest better real-life performance than before, as the all-important <200W efficiency is actually better than originally thought.